The present invention relates to lakeshore erosion. Typically, people attempt to stop such erosion by building seawalls. Such seawalls may be cast concrete or they may be heavy wood timbers, secured to pilings driven into the lake bed.
One problem with such seawalls is that the energy of an incoming wave goes straight down against the front of the wall as well as straight up. As a result, a depression develops in front of the seawall and it eventually sinks or collapses. Sometimes beach builds behind such seawalls for a time, but it tends to come and go.
Other more complicated devices have been tried with similarly mixed results. Recognizing the tendency of concrete blocks placed in the water to get undermined in the same manner as poured seawalls or wooden seawalls, one prior artisan has molded concrete "jacks" which have a plurality of projections radiating outwardly from a center. Such devices allow water to flow through while breaking up a wave to some extent. However, such devices do not consistently result in beach building up behind such devices. Basically, they tend to slow erosion rather than resulting in a reversal of the erosion process.
Soviet Union Pat. No. 1,133,328 discloses a beach block having a sloped front wall which terminates at its top in an upwardly projecting vertical front face. The block is designed for placing in the water with the water level at the top of the sloped front face and with the vertical wall projecting above the water level. There are apertures in the vertical wall to allow some water through. The Russian shows a plurality of the blocks positioned in the water in spaced relationship, rather than being joined together.
While some water containing sand is allowed through the openings in the vertical front wall of the block, the vertical wall tends to throw much of the wave water and the sand it contains back out toward the open sea. Also, it is believed that ice would tend to form within the openings in the vertical front wall and thereby tend to lift and move the blocks about during the wintertime. While it is not known whether or not the blocks of this device have ever been commerically used, it is believed that they would not perform satisfactorily to reverse lakeshore erosion.